Lux Aeterna
by Jennyyu73
Summary: Marks Institute is an elite private school that Sherlock and company all attend. However, behind its polished exterior lies many dark secrets and complications for the students, with one student aiming to cause havoc. AU, T for dark themes.
1. Sudden Impact

**A/N: The story title is inspired by the lovely song by Clint Mansell, meaning "eternal light". **

As always, the second day of school was much more interesting than the first.

However, the word "interesting" should not be taken to mean something pleasant, because the overall incident was rather unpleasant. It simply added a connotation that the thing had been... different.

To put it bluntly, a student by the name of Mary Morstan had committed suicide.

Sherlock wasn't one for being "in-the-know" about the latest school news or gossip– it simply did not interest him– but even he had heard about this.

New, much like a virus during flu season, traveled rapidly throughout the hallways of Marks Institute. It started from the very center of the information with with Molly Hooper, Mary's supposed best friend, and found its way to Sherlock's friend-acquaintance, John Watson, who then told him.

"Okay," He had said, as a response.

"Just 'okay'?!" John's voice grew in pitch, still shocked himself by this piece of fact.

"Was that not an adequately appropriate reaction? Let me try again." Sherlock sucked in a deep breath, then said in a slightly more baffled tone, "Are you serious?"

His friend-acquaintance shook his head, perplexed as always by his insensitivity. Of course, it wasn't really a surprise that Sherlock wasn't more emotional, as they have known each other for over six years now, and quite a lot has happened during that time. It now simply confused John, the way that he was always steely-faced (save those time when he needed to charm someone to get what he wanted) and nonreactive.

Nonetheless, John knew he wasn't going to get any more out of Sherlock, so he simply moved on to another topic of conversation, "So what did you think of the calculus test today? Easy?"

"Of course it was." This was always Sherlock's answer to any inquiry about tests. Although at first, he had transferred to this school looking for a challenge, his ambition soon faded when Marks was no more difficult than any other public schools he had attended before.

The school board first invited him when they saw his standardised test scores a few years back and offered a full scholarship. It had held the appeal of a new toy, exciting and captivating at first, but losing it after the initial few days. Then, it was just back to Sherlock wandering through the hallways again, avoiding most social interactions and attempting to escape the holds of boredom.

Boredom, oh the great, terrible feeling, was his arch nemesis, if there ever was such a thing.

It was one of the few things able to elicit a frustrated reaction from his normally composed self. Attempting to alleviate it was one of his constant pursuits, and one that had been futile so far. But maybe this death would change things...

* * *

"Anderson, Seth?" The gym teacher yelled out, holding a clipboard with one hand and a pencil in the other. The daily roll call.

"Here!" The teen called back, used to being first first on the list. After replying, he immediately turned to the person on his right and lowered his voice to a whisper, trying not to get eavesdropped upon. "Sally, did you hear about that Mary person?"

"Yes," Sally Donovan said, face in a thinking expression. "I don't really know her that well, but... why? I mean, she used to annoy me because she always seemed so cheery, but then all this madness. My dad said that he might send in some of his officers in to investigate, just to ensure that there wasn't any foul play involved." Her father was the owner of a very prominent private detective agency located in Winchester.

"Foul play?" Anderson frowned. "Like murder foul play?"

"It could be. You never know. You do have to admit that the circumstances seem a bit suspicious." The teacher reached her name on the list and she responded back with a loud, "Here."

"I don't know which would be worse, knowing that Mary was miserable enough to end her life or knowing that there is someone here on campus who is messed up enough to end her life." He fiddled around with his fingers, contemplating the notion.

Sally sighed, then shrugged. "Okay, call me terrible for saying this, but I think the second would be worse. For all of us, anyway. That would mean that everyone here is in danger, instead just Mary herself."

"Hey, pipe down," the teacher said, noticing the conversation held between the two. "Okay, everyone. The agenda for today is basketball..." He then went on to a ten-minute ramble about the basic concepts of the sport, and how no foul play was to be accepted in this class. Also not allowed in gym was any gum, food, or drinks, which evoked several groans from a group of girls as they walked off to a trash can to spit out their gum.

Sally and Anderson tuned out all of this.

Moving on from their initial topic, they were engaged in a heated debate about this show they were both watching last night, about who they thought was the culprit in the criminal case that the main protagonists were involved in. Both of them were extremely interested in the field of criminology, and part of that might be contributed to Sally's upbringing as a detective's daughter, but their mutual love of crime television programs was to blame as well. Perhaps they might even join Scotland Yard one day. That would certainly be exciting.

* * *

Molly Hooper was curled up on her couch this Tuesday morning on her couch with a large carton of cookie crumble ice cream, browsing the internet in order to distract herself.

It wasn't so much as a way to find solace as something to take her out of her own life for a little while.

The news had came to her very late last night with her mother receiving a call from Mary's parents. They hadn't divulged any details about the horrific event, just merely told them that Mary was no longer alive. It wasn't their fault that they were so curt and reluctant to disclose any details. The majority of the call was spent with Mr. and Mrs. Morstan attempting to sound coherent and not to break down during the middle of it.

Immediately afterwards, her mum told Molly that school tomorrow was absolutely out of the question and that she needed to stay home and try to get herself together, even though she was managing to keep herself collected throughout this ordeal.

Molly was what one might call an emotional person, although most outsiders were unable to tell because she does like to keep it inside. Displaying the feelings usually brought on a bout of attention from too many people, and mostly unwanted ones. So, she stayed quiet when told the news, and she stayed quiet even now.

If one doesn't talk about something, then that thing won't come up in thought. If it doesn't come up in thought, then it might as well never have happened, right?

No, that method won't work for this. She knew fully that it happened, and no matter how much she pushes it out of her mind, it slams back in.

So, in a fit of desperation, she jammed a pair of headphones in her ear and set the volume at the highest bar. Molly then searched through her music library and stumbled upon the perfect song for this occasion. She then stumbled into the bathroom medicine cabinet and took out a bottle of sleeping pills. Pouring two onto her palm, she swallowed them dry and flopped down onto her mattress.

After twenty minutes, she was finally able to get away from all this madness, if not only for eight hours, or however long the description on the bottle had said.

* * *

Jim Moriarty found Marks Institute to be a very fascinating place. Or rather, the students, aka his to-be classmates, are the ones who caught his attention. All of them seemed so perfect and well-rounded on paper– great grades, attendance, extracurricular, the works.

He had made sure that he did his homework and performed a background check on almost all of the four hundred students attending the school. Although the tech department did not realise it, the network had been so surprisingly easy to hack. However, that did not come as much of a surprise to him, most things in life were relatively easy for him. That's why he needed something more. There had been one specific student that caught his eye. One that went by the name "Sherlock Holmes", which sounded rather odd and a mouthful.

His record matched that of Jim's, their IQ's almost within a hair's breadth of each other, which he had been impressed at. He openly admitted that, not being one for humbleness, he was probably one the greatest minds in the country at the moment, albeit being merely seventeen years of age. Further more, he was the little brother of a man named Mycroft Holmes, who was rather well-recognized within the British government. So that made Sherlock someone with both brains and connections.

Other than what was on the school's database, the youngest Holmes seemed to be steering clear of any other records. That's alright, Jim liked a bit of a challenge.

He would rather like to get to know the youngest Holmes. He had a plan. With their combined intelligence, with them working together, who knows what they could accomplish? Well, he would have to make sure that he is the one with more authority, of course. But all that aside, Sherlock Holmes definitely seemed like a promising candidate for what he had in mind.

Perhaps it was time to turn a perfect place into chaos.

**A/N: I know Anderson's name was never revealed in the show, so I just plugged one in. Don't worry, he'll be referred to by his last name most of the time to avoid any confusions. **

**Thanks for reading, more to come soon! :) **


	2. First Impressions

**A/N: Hurray for sudden burst of inspiration. **

The student that stood in front of the calculus classroom was unfamiliar, yet he was staring relentlessly into Sherlock's eyes. Perhaps even uncomfortably so. Yes, definitely uncomfortably so.

"Let us give a warm welcome to a new student, Jim Moriarty. He just transferred here from America," Mrs. Morris announced in a droning voice, more of a formality than anything. She wasn't one for taking too much time doing things other than teaching. Sure enough, she told him to sit down immediately afterwards, without telling him to say an interesting fact about himself or something of the type like most other teachers would.

Sensing that she was eager to move on, Jim grew dilatory and said in a sardonic tone, "But wouldn't you like to ask about my experiences? Or maybe ask me something about myself? That's what all the other teachers do."

His accent was certainly a curious thing. A large chunk of it was definitely American, yet hidden beneath that was some sort of... Australian maybe? Aside from that, the way he said the words almost seemed childish. Surely he was no older than fifteen, yet something in his demeanour suggested he was way older. There was something in his eyes that seemed almost malicious.

Mrs. Morris appeared to be a bit flustered and unsure about how to proceed. She finally replied with, "Maybe after class. We have homework to go over first from last night."

Jim shrugged and walked, no it was more of a sashay, down the aisles of desks and plopped himself into a seat right next to Sherlock. He turned and grinned at the him.

Sherlock, although not paying attention to a word that the teacher was saying, still flippantly ignored him and pretended that something else occupied all his attention. He made a mental note to do some research tonight on Jim Moriarty. Something told him that he was bound to find some interesting stuff.

The class wrapped up rather quickly, and Mrs. Morris assigned them all several more problems to finish that night.

This was what Sherlock had disliked about math class. Nothing was ever _different_. It was always "learn material in class, work on homework, then test in a few days." No variation, nothing special. This method has made such a riveting subject hard to stomach.

Math, or specifically calculus, was actually a subject that could be categorised as fun. All the problems, all the puzzles, they made Sherlock anticipate the answers.

"Sherlock, it's time to go."

John's voice jerked him out of a partial reverie and he stood up and snatched his belongings. "Yes, I'm aware."

"Didn't seem like it," John said, part joking, part annoyed.

Their relationship was complicated indeed. It had started, approximately three years back, purely prompted by one of the counselors at the institute. Sherlock's parents had apparently worried that their youngest son was depressed and too antisocial. They called up the school and requested them to have a talk with him to try to find out what was wrong. Nothing was wrong, Sherlock had protested, but he was also amused at the futile attempts of the counselor to psychoanalyse him.

Psychoanalyse _him_. What a joke.

What came out of those meetings was that the school officials had actually assigned him a friend. One of Marks Institute's aims is to appease its students, mainly due to the fact that the majority of the students' parents are filthy rich.

Sherlock's parents happened to match that description, and so, with great care, the officials searched through a sea of student profiles and stumbled upon a scholarship student named John Watson.

They didn't straight out tell John that he had to become Sherlock's friend, obviously but it was more of a gradual process where they put the two in almost every single class together. After so much time together, it was inevitable that they began to at least tolerate each other. With toleration (and a whole pile of group projects that they were placed together to finish), some sense of friendship finally grew.

However, their friendship was strenuous at times and they have been fed up with each other for plenty of times, but when it came down to it, John was Sherlock's only true friend at the school and Sherlock was John's peek into the life of a privileged family. Which is to say that he reaped some benefits in the form of small monetary assistance here and there if cash ever ran tight. It wasn't easy having to live on ramen noodles and macaroni and cheese for the majority of the times, so Sherlock took it upon himself to give John enough money to buy decent food.

John was not totally happy with the whole arrangement, with his role as a charity case, but part of him figured that putting up with Sherlock and enduring his antics was certainly difficult enough to warrant some form of settlement.

Over the years, the two had actually warmed up to each other, yet a large majority of conversations between the two seemed like a constant fencing match of sarcastic comments.

"So, does the oh-so-broody Sherlock Holmes feel up to a short field trip this afternoon, after school?" John declared.

"The oh-so-broody Sherlock Holmes might be interested if the oh-so-ambiguous John Watson elaborated a bit on what he meant by 'short field trip'."

"I mean, we should go visit Molly to see how she's coping. You know, with the whole Mary incident." They were, by a stretch of the word, friends. However, visits to each other's houses was not rare, as their parents all have a mutual association with each other.

"I'd rather not," Sherlock murmured absentmindedly, attention caught now by the new student who was staring intently at him from across the halls. Jim Moriarty was not even attempting to disguise his gaze, and did not say anything when Sherlock noticed. He merely cocked his head to the side and slowly looked away. "I have things to attend to. Experiments to run."

"Or, you're saying that just as an excuse to get out of this, even if you have no intention to do any of those things," John rolled his eyes. This was to be expected. Molly was probably at a vulnerable time right now, and his friend did not deal too well with people who are emotionally compromised. He had seen Sherlock at his grandfather's funeral last year, and not a tear was shed. In fact, he had been spacing out during the entire event, and looked rather uncomfortable when guests went up and offered their condolences to him and his crying parents.

"You know me so well." There was possibly a hint of sarcasm to it.

"We're going." A command this time, no room for trying to wiggle out of it. "No use in refusing."

Sometimes, friends can be such a bother.

* * *

Sally Donovan and Seth Anderson are not too often seen without the company of each other. Aside from the occasional classes that they do not share, the majority of their time are spent together, talking about nonsensical topics and doing nonsensical things.

From an outsider's perspective, they would certainly be considered a couple, but Sally vehemently denies the notion. She considers him her best friend, and any feelings present are purely platonic.

Their history has been lengthy, and filled with quite a number of fights. But that wasn't unusual for a friendship.

The real story lies within the way they first met each other.

It was the first day of their third year, as Marks Institute offers education from grade one through twelve. Anderson was being, well, there was no phrasing than "a little shit". It was likely induced by his privileged lifestyle that he had gotten used to at home, being used to getting his way. A classic brat, one could say. His parents waved it off, sure that he will grow out of it. Their passivity was probably a factor in that as well.

He had tossed insults left and right at Sally, especially directing it at her hair, which she had made clear that she was not fond of.

It went something along the lines of: "Ha! Your hair looks like those cheap swirly ramen noodles that poor people buy!" "Shut up! Those things are actually good." "You eat ramen noodles? What a loser." "I said shut up!" "Make me." "I will." "Huh, what are you going to do? Punch me? Girls can't punch."

So, she punched him in the nose. The way she threw her first was even something that could be taken as artistic. The dark red liquid that spilled out of Anderson's nose surprised both of them.

But no matter, they were both sent to the headmaster's office and parents were called.

Their punishments were dealt, which was a week's suspension for Sally and a hospital visit for Anderson. Just as she was about to complain about the unfairness, Anderson jumped in and said, "Why is she being punished? She's the one that proved me wrong when I said girls can't punch."

As mellow as that might be, Sally was still suspended. It was, though, the start of a mutual respect between the two, and something that brought them to this point.

They were walking through the hallways, conversing between the five minutes of free time allotted between classes. Anderson suddenly remarked, "Isn't cutting off the branches of a tree sort of like amputation?"

"What?"

"Just a thought."

They continued walking.

* * *

Calculus for Moriarty was infuriatingly, gut wrenchingly boring. It had been slightly amusing at first, taking a small dig at the teacher, but things went downhill quickly after that.

He had finished university-level education just last year, so anything taught in the class, he would already know. A quick survey around the room informed him that there wasn't anyone he would be interested in knowing, except possibly for the Sherlock Holmes that he did so much research on. It wasn't quite difficult for them to be assigned to the same class– all it took was a check slid under the radar from his hand to another.

But Sherlock wasn't completely devoid of faults, either. He looked so much more ordinary than Moriarty previously thought. Except for his unusually sharp cheekbones and thin stature, there was nothing that made the youngest Holmes stand out from the rest of their classmates, nothing that could've indicated that he was a qualified genius. Moriarty took it upon himself to grin at the teenager nonetheless. Some intuition told him that it would certainly capture Sherlock's attention.

A brief once-over told Moriarty that Sherlock had not bothered to brush his hair that morning, that he had nothing but coffee for breakfast, and that he was just as bored, if not more, than Moriarty was.

Mrs. Morris interrupted his perusing with a question about the instantaneous change of a function on the board. He answered without missing a beat, giving her a small smile in the process, knowing that she thought she caught him off-guard.

Guards are never meant to be lowered, and lowering them was certainly considered stupid in Moriarty's book. There was a reason why he masked his true emotions to everyone, no matter who they were. It was best to fake what they wish to see, it made people leave him alone when they realise that he was not going to contribute to further conversations. Which was why small talk was something he wish to kindly bury a hatchet into. They were words that people who have nothing interesting to say use to fill up silence.

Those thoughts, however, were not at all helpful in his attempt to grow closer to Sherlock and set his plan in motion. Therefore, as soon as he parted ways with the other student, whom Moriarty guessed was John Watson, he sidled up the the youngest Holmes and introduced himself.

"Hello, I'm Jim. Jim Moriarty."

"I am well aware of that fact. It has only been forty-five minutes since Mrs. Morris announced your name to the entire calculus class. Surely that wasn't an implication that my memory is somehow faulty."

"Oh, not at all, I was just making conversation. Isn't that what people do?"

Sherlock shrugged and seemed eager to be relinquished from this conversation. "Are you doing that in hopes we'll become friends?" He quickened his pace in the hallways, and Moriarty rushed forward to keep up.

"Yes, friends, that'd be a nice start."


End file.
